how to get the longest ordered sub sequence of a
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From: Bob Hanlon on 10 Sep 2009 07:22 data = RandomInteger[{0, 9}, 50] {1,9,6,7,9,8,2,2,2,1,4,0,9,9,9,2,8,2,8,0,1,4,4,3,4,9,9,4,2,6,9,4,9,8,4,3,9,4,0,5,1,7,2,0,7,2,6,2,1,6} Select[sdata = Split[data, #2 < #1 &], Length[#] == Max[Length /@ sdata] &] {{9, 8, 4, 3}} Select[sdata = Split[data, #2 <= #1 &], Length[#] == Max[Length /@ sdata] &] {{9, 8, 2, 2, 2, 1}} Select[sdata = Split[data, #2 > #1 &], Length[#] == Max[Length /@ sdata] &] {{6, 7, 9}, {0, 1, 4}, {3, 4, 9}, {2, 6, 9}} Select[sdata = Split[data, #2 >= #1 &], Length[#] == Max[Length /@ sdata] &] {{0, 9, 9, 9}, {0, 1, 4, 4}, {3, 4, 9, 9}} Bob Hanlon ---- a boy <a.dozy.boy(a)gmail.com> wrote: ============= how to get a (strict or not-strict)decreasing sub sequence of a list? ---------------- increasing ?
From: Fred Simons on 10 Sep 2009 07:25 a boy wrote: > how to get a (strict or not-strict)decreasing sub sequence of a list? > ---------------- > > increasing ? > > > lst=RandomInteger[{1,100}, {5000}]; With[{sublists=Split[lst, #1<#2&]}, With[{m=Max[Length /@ sublists]}, Select[sublists, Length[#]==m&]]] {{3,19,22,33,51,66,89,95}} Fred Simons Eindhoven University of Technology
From: DrMajorBob on 11 Sep 2009 05:26 I've been assuming the OP wanted the LONGEST increasing subsequence. But he never said that. D'oh! Bobby On Thu, 10 Sep 2009 06:24:48 -0500, dh <dh(a)metrohm.com> wrote: > > > Hi, > > we can do this with intermediate variables. > > E.g. assume the data is in d: > > d = RandomInteger[10, 12] > > then we get an non-strict increasing sub list by: > > t = d[[1]]; > > Select[d, If[# >= t, t = #; True, False] &] > > the following gives a strict increasing sub list, without the first > > element, that we need to append later: > > t = d[[1]]; > > Select[d, If[# > t, t = #; True, False] &] > > Daniel > > > > a boy wrote: > >> how to get a (strict or not-strict)decreasing sub sequence of a list? > >> ---------------- > >> > >> increasing ? > >> > > > -- DrMajorBob(a)yahoo.com
From: DrMajorBob on 11 Sep 2009 05:27
> I've been assuming the OP wanted the LONGEST increasing subsequence. > > But he never said that. Oops, yes he did... in the subject line... and the code below doesn't do it. Bobby On Thu, 10 Sep 2009 18:08:18 -0500, DrMajorBob <btreat1(a)austin.rr.com> wrote: > I've been assuming the OP wanted the LONGEST increasing subsequence. > > But he never said that. > > D'oh! > > Bobby > > On Thu, 10 Sep 2009 06:24:48 -0500, dh <dh(a)metrohm.com> wrote: > >> >> >> Hi, >> >> we can do this with intermediate variables. >> >> E.g. assume the data is in d: >> >> d = RandomInteger[10, 12] >> >> then we get an non-strict increasing sub list by: >> >> t = d[[1]]; >> >> Select[d, If[# >= t, t = #; True, False] &] >> >> the following gives a strict increasing sub list, without the first >> >> element, that we need to append later: >> >> t = d[[1]]; >> >> Select[d, If[# > t, t = #; True, False] &] >> >> Daniel >> >> >> >> a boy wrote: >> >>> how to get a (strict or not-strict)decreasing sub sequence of a list? >> >>> ---------------- >> >>> >> >>> increasing ? >> >>> >> >> >> > > -- DrMajorBob(a)yahoo.com |